多效唑对不同生境多年生黑麦草抗旱性的影响

Effects of paclobutrazol on drought resistance of Lolium perenne ‘Bomber'under different growing conditions

本研究以北方园林草坪中的常用草种多年生黑麦草‘轰炸机’(Lolium perenne‘Bomber’)为研究材料,为解决控制草坪用水的实际问题,分别在温室和大田模拟干旱胁迫,对多年生黑麦草施用不同浓度多效唑(PP333)处理,研究其生理变化特征。结果表明,多效唑处理后,与未处理相比,叶片各项生理指标在轻度胁迫(10d)时没有表现出明显不同,但在中度胁迫(20d)和重度胁迫(30d)时表现出显著差异(P<0.05);叶片相对含水量(RWC)呈现下降趋势,相对电导率、丙二醛含量和游离脯氨酸含量升高,超氧化歧化酶活性呈现先升高后降低的变化;综合各项生理指标的变化规律,施用浓度为200mg·L-1的多效唑可以提高多年生黑麦草的抗旱性;相同程度的干旱胁迫下,大田苗的受伤害程度要小于温室苗,表明草坪草的实际耐旱性要强于温室干旱条件下。

Lolium perenne cv.‘Bomber＇is widely applied as turf grass species in the garden lawn of north China.In the present study,the physiological characteristics of‘Bomber＇with different concentrations of PP333 treatments under drought stress in both greenhouse and the field were evaluated to provide reference for solving the practical water shortage problems in turfgrass management.The results revealed that the physiological indices of‘Bomber＇leaves after PP333 application had no significant difference under short stress period（10d）,while had significant differences under moderate stress period（20d）and long stress period（30d）.During drought stress,the leaf relative water content（RWC）declined,whereas the relative conductivity,malondialdehyde（MDA）content and free proline content increased and super-oxide dismutase（SOD）activity fluctuantly changed.Based on these comprehensive responses of physiological indices,PP333 application with the concentration of 200 mg·L^-1 can improve the drought resistance of L.perenne.Under the same degree of drought stress,the seedling damage in the field was far less than those in the greenhouse,which indicated that the actual drought tolerance of turfgrass was stronger than the experimental results under the greenhouse drought condition.